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• how to make any filter's value that accept integer value be a function of the timestamp in ffmpeg ? [closed]

  30 novembre 2023, par rosner altamira

  For example, i am trying to apply blur effect to video in ffmpeg using gblur filter, i want the blur strength to gradually increase from 0 to 50 in 2 secs starting at 5 secs and fade back from 50 to 0 in 3 secs thus finishing at 15 secs. In summary the blur is between 5 and 15 secs but from 5 to 7, the effect will gradually grow from 0 to 50 and from 12 to 15 it will fade from 50 back to 0.

  


  here is what i tried :

  


  


  ffmpeg -i test-video.mp4 -loop 1 -t 5 -i test-image.jpg -filter_complex "[0:v]gblur=sigma='if( lte(t,5) + gte(t, 15), 0, if( between(t, 7, 12), 50, min( max(25t - 125, 0), max(-16.67t + 250, 0) ) ) )':enable='between(t,5,15)'[bg] ;[1:v]fade=in:0:30[ol] ;[ol]fps=fps=15[ol] ;[bg][ol]overlay=(W-w)/2 :(H-h)/2:enable='between(t,5,15)'[out]" -map "[out]" -map 0:a output_video.mp4

  


  


  Expectations :

  


  


  [0:v]gblur=sigma='if( lte(t,5) + gte(t, 15), 0, if( between(t, 7, 12), 50, min( max(25t - 125, 0), max(-16.67t + 250, 0) ) ) )':enable='between(t,5,15)'[bg] :

  


  


  The blur strength depends dynamically on the time (t) as described above, controlled by the expression.
The enable parameter ensures that this filter is only applied between 5 and 15 seconds.

  


  


  [1:v]fade=in:0:30[ol] :
[ol]fps=fps=15[ol] :
[bg][ol]overlay=(W-w)/2 :(H-h)/2:enable='between(t,5,15)'[out] :

  


  


  The overlay input should be faded in for 2 secs starting from 5secs and will last 10secs (same time for the blur)

  


  As result, i am getting Invalid char error. Seems like sigma does not accept the "t" timestamp variable.

  


• Extracting CEA-708 closed captions from MPEG-TS stream with FFmpeg

  20 août 2021, par Brad

  I have an MPEG-TS stream delivered over HTTP from an ATSC 1.0 receiver :

  


  Input #0, mpegts, from 'http://example.com/stream':
  Duration: N/A, start: 33532.329189, bitrate: N/A
  Program 3
    Stream #0:0[0x31]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, top first), 1920x1080 [SAR 1:1 DAR 16:9], Closed Captions, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
    Side data:
      cpb: bitrate max/min/avg: 15836400/0/0 buffer size: 7995392 vbv_delay: N/A
    Stream #0:1[0x34](eng): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, 5.1(side), fltp, 384 kb/s
    Stream #0:2[0x35](spa): Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 128 kb/s (visual impaired)


  


  How can I extract its closed caption data ?

  


  I've read that for files, I can use lavfi :

  


  ffmpeg -f lavfi -i movie=input.ts[out+subcc] ...


  


  However, this doesn't work for streams over HTTP. At least, I can't figure out how to properly escape/quote the URL for use in the lavfi input syntax.

  


  Any suggestions ?

  


• "Output stream closed" when streaming PassThrough stream to AWS using @aws-sdk/lib-storage

  5 avril 2023, par cjd

  I am attempting to stream a PassThrough stream directly to S3 using @aws-sdk/lib-storage.

  


  My upload function is :

  


  const uploadStreamToS3 = () => {
    const Key = 'test.mp4';
    const Bucket = 'bucket-name';
    const stream = new PassThrough();
    const upload = new Upload({
        client: s3Client,
        params: { Bucket, Key, Body: stream },
        tags: [], // optional tags
        queueSize: 4, // optional concurrency configuration
        partSize: 1024 * 1024 * 5, // optional size of each part, in bytes, at least 5MB
        leavePartsOnError: false // optional manually handle dropped parts
    });
    return {
        stream,
        uploadComplete: upload.done(),
        upload
    };
};


  


  I am piping from ffmpeg directly to the PassThrough stream :

  


          ffmpegInstance
            .addOutputOptions(
                '-movflags +frag_keyframe+separate_moof+omit_tfhd_offset+empty_moov'
            )
            .format('mp4')
            .pipe(stream, { end: true });


  


  When I run this locally, everything works.

  


  I am using a container lambda function with Docker.

  


  If I run the Docker container locally, everything works as expected. If I run the same code on Lambda, I get the following error Output stream is closed.

  


  One work around is to write the file to the Lambda tmp folder using a writeStream and once the file is written I can stream the file to S3 using a readStream as the Body of new Upload. However, I would like to stream directly to S3 and not create this temporary file in Lambda.

  


  Is this possible ? Is the issue with using a PassThrough stream in the Body for S3 ?